Pick a top collection:
audio audio
data data
education education
etree etree
image image
movies movies
netlabels netlabels
software software
texts texts
web web
Or:
Number of total public items* (over 15.3 years)
* Prior to 2015, only movies, audio, texts, and etree items were tracked,
with web items added May 2013. (All items tracked as of 2015.)